The Princeton, New Jersey, man known as a star student in high school, who is now accused of killing his brother and a family cat in a “fit of madness” last month, is scheduled to appear in court Monday afternoon.

Matthew Hertgen, 31, is accused of murdering his 26-year-old brother, Joseph Hertgen, in the family’s Princeton apartment, allegedly with a knife and golf club. He is also charged with animal cruelty related to the death of a cat.

Monday’s hearing in Mercer County Superior Court is a pre-indictment conference – a procedural hearing that likely won’t last long, according to the court. 

Earlier this month, Hertgen consented to pretrial detention, meaning the prosecution didn’t need to show evidence proving why he should be held in jail before his trial.

Matthew Hertgen and his brothers, left. The 31-year-old, right, is accused of killing his younger brother, Joseph.

Joseph and Matthew Hertgen were star soccer players in high school and college. They were both athletes at Toms River High School, and Matthew went on to study at Wesleyan University in Connecticut. Joseph Hertgen was recruited to play soccer at the University of Michigan.

“If I was [the] defense attorney, I wouldn’t fight it. I would say, you know what? We think there’s a mental issue,” Gelman said.

The public defender’s office, which is representing Hertgen, told Fox News Digital that its attorneys do not comment on pending cases.